text = "To be or not to be,that is the question."

letters_set = set()
letters_count = {}

for char in text:
    if char.isalpha():
        letters_set.add(char.lower())
        if char.lower() in letters_count:
            letters_count[char.lower()] += 1
        else:
            letters_count[char.lower()] = 1

for letters in letters_set:
    count = letters_count[letters]
    print(f"{letters}:{count }")
